The fluid rearrangement and entangling of fibers to produce non-woven fabrics has been commercially practiced for many years. See for instance, Kalwaites, U.S. Pat. Nos. 2,862,251 and 3,033,721; Griswold et al., U.S. Pat. No. 3,081,500; Evans, U.S. Pat. Nos. 3,485,706; and Bunting et al., U.S. Pat. No. 3,493,462. This basic technology has been used to produce a wide variety of non-woven fabrics.
U.S. Pat. No. 3,486,168 discloses an unapertured ribbed entangled non-woven fabric. The fibers are supported on a "grill" during entangling. In one embodiment the fabric comprises parallel entangled ribs with a substantially continuous array of fibers extending between the ribs. U.S. Pat. No. 3,498,874 discloses an apertured ribbed entangled non-woven fabric. During entangling the fibers are supported on a plain weave carrier belt having heavier wires or filaments in one direction and three to five times as many finer wires or filaments extending in the other direction. The fabric formed thereon displays zig-zag entangled ribs extending in said one direction.
Co-pending application Ser. No. 602,877 filed Apr. 23, 1984, and now U.S. Pat. No. 4,612,226, discloses an apertured entangled non-woven fabric comprising two series of fibrous bands that are substantially perpendicular to each other. Each band contains segments in which the individual fibers are substantially parallel to each other, these segments alternate with regions of entangled fibers which occur when the band of one series intersects a band of the other series. The fabric is entangled on a plain weave belt.
U.S. Pat. No. 4,379,799 to Holmes et al. utilizes fluid rearrangement and entanglement to provide a non-woven fabric having the appearance of ribbed terry cloth, by carrying out the fluid rearrangement/entanglement on a woven belt having fine threads or filaments extending in one direction and fine threads or filaments and heavier threads extending in the other direction. The non-woven fabric provided therein is characterized by a repeating pattern of spaced, paralleled, raised ribs which extend continuously in one fabric direction, with the ribs being interconnected by spaced bundles of straight, substantially parallel fiber segments, said bundles being substantially parallel to one another and substantially perpendicular to said ribs. Adjacent bundles and the ribs they interconnect form apertures. The fibers in the ribs are almost wholly entangled throughout. On a macroscopic scale when viewing the fabric as a whole, the ribs are uniform and substantially non-patterned. The fabric of Holmes et al. are described as having typical basis weights of 1.5 oz. to 6 oz. per square yard.
The fabric of the present invention is made on the particular type of carrier belt described in Holmes et al. The fabric of the present invention have a basis weight of from 0.03 to 1.5 oz/yd.sup.2. They are made from a starting web of carded fibers comprising at least 75% polyester staple fibers. While the fabrics of the present invention do not display ribs which are almost wholly entangled throughout, they exhibit excellent strength in both the machine and cross direction.